diff options
| author | Jim Wilson <jimw@sifive.com> | 2020-06-02 11:19:39 -0700 |
|---|---|---|
| committer | Jim Wilson <jimw@sifive.com> | 2020-06-02 11:44:44 -0700 |
| commit | 4013baf99c38f7bca06a51f8301e8fb195ccfa33 (patch) | |
| tree | eb2611cf552e6acf4c9eaeb55b33f1ec3d9d46c2 /libgcc | |
| parent | 578c013aa697cb81a46e9b335ce61c82c009c77f (diff) | |
RISC-V: Make __divdi3 handle div by zero same as hardware.
The ISA manual specifies that divide by zero always returns -1 as the result.
We were failing to do that when the dividend was negative.
Original patch from Virginie Moser.
libgcc/
* config/riscv/div.S (__divdi3): For negative arguments, change bgez
to bgtz.
Diffstat (limited to 'libgcc')
| -rw-r--r-- | libgcc/config/riscv/div.S | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/libgcc/config/riscv/div.S b/libgcc/config/riscv/div.S index 151f8e273ac..17234324c1e 100644 --- a/libgcc/config/riscv/div.S +++ b/libgcc/config/riscv/div.S @@ -107,10 +107,12 @@ FUNC_END (__umoddi3) /* Handle negative arguments to __divdi3. */ .L10: neg a0, a0 - bgez a1, .L12 /* Compute __udivdi3(-a0, a1), then negate the result. */ + /* Zero is handled as a negative so that the result will not be inverted. */ + bgtz a1, .L12 /* Compute __udivdi3(-a0, a1), then negate the result. */ + neg a1, a1 - j __udivdi3 /* Compute __udivdi3(-a0, -a1). */ -.L11: /* Compute __udivdi3(a0, -a1), then negate the result. */ + j __udivdi3 /* Compute __udivdi3(-a0, -a1). */ +.L11: /* Compute __udivdi3(a0, -a1), then negate the result. */ neg a1, a1 .L12: move t0, ra |